There should be a plastic mesh filter in place. About 2 x 18 inches, give or take. 

Karl Wolz
Sent from my electronic umbilicus

> On Feb 19, 2014, at 7:21 AM, Jarrett Kupcinski <kupcinski@GMAIL.COM> wrote:
> 
> I'm replacing the front heater fan, and so I'm doing a bit of cleaning in the heater box. I was astounded to find a collection of butterfly wings inside the box. I know every van should have a hobby, but I'd rather mine not do this at the expense of cabin air-flow.
> 
> Has anyone rigged up any kind of fresh-air filter on their van? Perhaps something outside, underneath the front grille? 
> 
> Jarrett Kupcinski
> 89 Bostig'd Westy